Study of the Corrosion Characteristics of Tunnel Fissures in a Karst Area in Southwest China

Table 1

Formation lithology of the Wulong tunnel area.

System	Formation		Lithology
Jurassic	Zhenzhuchong	J1z	Dark-brown shale and mudstone, light-gray sandstone
Triassic	Xujiahe	T3xj	Dark-brown shale, light-gray sandstone
	Leikoupo	T2l	The upper part is dark-brown shale and marlstone. The middle part is dark-brown shale and light-gray sandstone. The lower part is gray limestone
	Jialingjiang	T1j	Gray limestone intercalated with dolomitic limestone
	Feixianguan	T1f	Gray limestone, dark-brown shale
Permian	Changxing	P2c	Dark-gray limestone
	Wujiaping	P2w	Dark-gray limestone
	Maokou	P1m	Gray and dark-gray limestone
	Liangshan	P1q+l	Limestone intercalated with bioclastic limestone
Silurian	Luoreping	S1lr	Gray and dark-gray mudstone